During production of a document, updates to the document may be made. For example, segments of the document may be updated with new images, text content, data values, etc. The segments may be used to automatically generate the document. In some cases, a rendering engine may automatically generate a document and a graphics operator may adjust the layout using a layout application, for example to fine tune the layout in ways that provide a visual effect desired by the graphics operator. Many people may be involved in the document production process, and a number of producers may be responsible for producing document data. A person responsible for one or more aspects of the visual appearance of the document, such as a graphics operator, may desire control over the incorporation of changes into a document and/or visibility into how individual changes to text, graphics, data, etc. will affect the visual appearance of the document. Typically, changes made to images, text, or other data incorporated into a document, such as by automatically generating the document at least in part by incorporating such content from one or more data sources, have been incorporated into the document all at once, e.g., by regenerating the document or a portion thereof to cause the updated content to be incorporated. In some cases, a graphics operator may not have generated a change herself and may not be familiar with it, and in any event if the changes are numerous and/or the document large, it may be difficult and/or time consuming for the graphics operator to ensure that individual changes incorporated using such an approach have had an effect on the visual appearance of the document, such as may require an adjustment by the graphics operator to the layout, formatting, etc. of the document and/or its content. In some cases, it might be desirable to be able to permit some changes to be made and yet reject others, which also is difficult to do under the above approach. Improved control of updates to a document, and the ability to view how changes will affect the visual appearance of a document, would be useful.